Croaks

What our animals are doing this month.

August 29, 2019 by editor

What our animals are doing this month… September 2019

As we head towards the end of summer we reach the period where newts will leave ponds for the year, with most newts having left their pond by the end of August. Overwintering newts or those still in the process of metamorphosis may still be present within a pond however. Great crested newts may move up to 120m in a night and may disperse up to 1km in total.

These movements will be dictated by the availability of surrounding habitats in addition to any barriers present that may be a problem such as roads, which can reduce habitat connectivity and cause road mortality for amphibians. Adult newts are more likely to engage in short-term migration with juveniles responsible for long-term and wider ranging dispersal throughout the landscape and between other sub-populations. Studies have also suggested that female newts are involved in longer distance movements than males.

Newts still in the process of metamorphosis will also disperse in due course. Great crested newt larvae will reach a length of 50 – 90mm before metamorphosis, smooth newt larvae at 30 – 45mm and palmate newt larvae at 25 – 40mm. During this process they will grow legs and absorb their external gills which are replaced by lungs to breathe air.

Remember to record your sightings of amphibians and reptiles on our Dragon Finder app.

*Fig 1: Great crested newts on the move as our summer months head to a close [Credit: Lin Wenlock]*

Croaking Science: Unisexuality- an alternative reproductive strategy

July 30, 2019 by editor

Approximately 90 vertebrate species are known to exist as unisexual populations, that is, consisting of reproducing females (Lampert & Schartl, 2010). All of these are restricted to fish, amphibian and reptile species (Figure 1). An all-female reproducing population has advantages since every individual can carry young so the population has the potential to grow at a faster rate than bisexual populations, where the male only donates sperm and does not produce offspring. Since this has a distinct advantage it is perhaps unusual that unisexual populations are so rare. However, the main cost of being unisexual is the loss of genetic recombination which occurs in male and female bisexual populations. This is crucial in providing genetic stability, preventing accumulation of mutations and providing opportunities for adapting to a changing environment. Therefore, unisexual species do not occur widely amongst vertebrates.

***Figure 1.*** *The Caucasian rock lizard is one of a few lizards which are unisexual*
[Photo credit: Alastair Rae, https://commons.wikimedia.org/wiki/File:Caucasian_Rock_Lizard_(34598190795).jpg]

Unisexual reproduction is often referred to as parthenogenesis, which is “reproduction in the absence of fertilization of the egg” (Lampert & Schartl, 2010). However, there are different forms of parthenogenesis which do allow some genetic exchange. True parthenogenesis occurs in females in the complete absence of males. This is incredibly rare and is known only from a handful of vertebrate species. However, one other type of parthenogenesis, known as gynogenesis, occurs when male sperm is used to trigger development of the female’s embryo. In this circumstance, the female does not incorporate any of the sperm’s genetic material and she uses all of her own so the sperm’s genome is redundant. However, in some situations, known as kleptogenesis, the female may incorporate some of all of the sperm’s genome thus resulting in offspring that have, 2, 3 or 4 times the amount of genetic material (diploid, triploid or tetraploid respectively) (Bogart et al., 2007). Since they ‘steal’ gametes of sexual species for their own reproduction, they are considered to be sexual parasites of their (usually parental) host species (Mikulíček et al., 2014). A third type of parthenogenesis is hybridogenesis where the eggs of a unisexual female are fertilised by the sperm of a closely related bisexual male. However, this genetic material is only incorporated into the new genome for one generation and is excluded when this female produces her own eggs (Lambert et al., 2010). Therefore, only maternal genes are passed onto subsequent generations. All these forms of parthenogenesis result in the inclusion of ‘fresh’ genetic material into the female thus improving the fitness of populations and increasing their robustness to resist diseases.

***Figure 2.*** *Four species of Ambystoma salamander which may be included in the nucleus of unisexual individuals.* [Photo credit: Bogart *et al*., 2007.]

Two main groups of amphibians are known to exhibit unisexuality. Unisexual mole salamanders (genus Ambystoma), occur in North America and generally have between two and five times the normal complement of genetic material compared to bisexual Ambystomid salamanders (Figure 2). These Ambystomid unisexual individuals are the oldest known group of unisexual vertebrates, having occurred for over 5 million years (Gibbs & Denton, 2016). The DNA in the nucleus of unisexual individuals is usually composed of genetic material from several species including: the blue spotted salamander (Ambystoma laterale), Jefferson salamander (A. jeffersonianum), small-mouthed salamander (A. texanum) and tiger salamander (A. tigrinum). This leads to a large range of possible genetic combinations with genetic material from the blue spotted salamander being present in most unisexual individuals. Female unisexual salamanders require sperm from a bisexual salamander species which are living in the same area to initiate reproduction. However, they can then either use the sperm solely to activate egg development (i.e. gynogenesis) or incorporate the sperm genome into the resulting offspring (Bogart et al., 2007). If genetic material from the sperm is used during reproduction, either the DNA is retained, resulting in the offspring with additional genetic material, or it is replaced. In a recent study, Gibbs & Denton (2016) studied the genetic exchange in unisexual populations of Ambystomid salamanders to try and explain how unisexual populations have persisted in the environment for 5 million years. They found that unisexual individuals gain enough genetic material through the occasional process of obtaining DNA from males to allow populations to remain robust and able to withstand environmental change. Therefore these individuals gain all the advantages of being unisexual, with also some of the advantages of sexual reproduction i.e. genetic mixing.

***Figure 3.*** *Two edible frogs (Pelophylax esculentus).* [Photo credit: Awewewe,]

One of the well-known breeding systems involving hybridogenesis is that of the water frog (Pelophylax esculentus) complex (Ranidae), widely distributed in Europe, which has considerable variation in types of hybridogenesis (Figure 3). The Pelophylax esculentus complex consists of two parental species, the marsh frog (P. ridibundus) and pool frog (P. lessonae), and their hybridogenetic hybrid the edible frog (P. esculentus). Edible frogs usually contain genetic material from both parental species. In most of its range, the edible frog reproduces hybridogenetically with the pool frog. However, during reproduction the pool frog genome is lost in the eggs and sperm. Therefore, pool frog DNA is not passed down to subsequent generations and the edible frog is considered a sexual parasite (Christiansen et al., 2005). However, many variations of this mating system occur across the species’ range. In most cases, female edible frogs will use the genetic material from the male, but it is not fully incorporating it into its genome. Due to the unusual genetic combining during hybridogenesis the presence of edible frogs can result in loss of the parental pool frog and marsh frog genotypes and is a potential conservation problem when it occurs in these populations.

Overall, unisexuality in amphibians represents a unique form of reproduction that has remained evolutionarily stable for several million years through occasional genetic mixing from the same or closely related species. Ambystomid salamanders and water frogs have proved highly successful at unisexual reproduction which is otherwise a rarely used breeding strategy amongst vertebrates.

References

Bogart, J.P., Bi, K., Fu, J., Noble, D.W.W. & Niedzwieckim, J. (2007) Unisexual salamanders (genus Ambystoma) present a new reproductive mode for eukaryotes. Genome, 50: 119–136.

Christiansen, D.G., Fog, K., Pedersen, Bo V. & Boomsma, J.J. (2005) Reproduction and hybrid load in all-hybrid populations of Rana esculenta water frogs in Denmark. Evolution, 59 (6): 1348–1361.

Gibbs, H.L., & Denton, R.D. (2016) Cryptic sex? Estimates of genome exchange in unisexual mole salamanders (Ambystoma sp.). Molecular Ecology, 25: 2805–2815.

Lampert, K.P. & Schartl, M. (2010) A little bit is better than nothing: the incomplete parthenogenesis of salamanders, frogs and fish. BMC Biology, 8: 78-80.

Mikulíček, P., Kautman, M., Kautman, J. & Pruvost, N.B.M. (2014) Mode of hybridogenesis and habitat preferences influence population composition of water frogs (Pelophylax esculentus complex, Anura: Ranidae) in a region of sympatric occurrence (western Slovakia). Journal of Zoological Systematics & Evolution Research. doi: 10.1111/jzs.12083.

Croaking Science: Ancient giants – new insight into the largest living salamanders

June 29, 2019 by editor

Cryptobranchids are giant salamanders which inhabit cool, flowing freshwater in Japan, China and North America. They are an ancient group and are regarded as living fossils that have remained little changed for over 160 million years (Gao & Shubin, 2003). There are just three known species within two genera, all of which are classified as Threatened or Near Threatened. The Chinese giant salamander (Andrias davidianus) is the largest in the world growing to 1.7 m in length and weighing up to 60 kg (Murphy et al., 2000) (Figure 1). This species is Critically Endangered due to threats from over-harvesting and habitat destruction. The Japanese giant salamander (Andrias japonicus) is a closely related species and is slightly smaller than A. davidianus. Although classified at Near Threatened by the IUCN, its habitat is highly fragmented and populations are declining in many parts of its range (Kaneko & Matsui, 2004). The North American hellbender (Cryptobranchus alleganiensis) is the largest salamander in North America, reaching up to 74 cm in length (AmphibiaWeb, 2019). All giant salamanders live secretive lives but have similar ecology and biology, which includes extreme longevity (up to 60 years), parental care by males, and large larvae. However, there are differences in their habitats, diets, reproductive behaviour, egg size and mating strategies (Lou et al., 2018). Although various studies have been carried out on these species, their behaviour and ecology is still poorly understood, and often published research is in national languages which is not readily accessible. Also, much evidence of their behaviour is through occasional observations and not systematic studies (Lou et al., 2018). In this article we highlight some recent research findings of these unusual and important species.

***Figure 1.*** *The Chinese giant salamander is the largest salamander in the world growing up to 1.7 metres long.* [Photo credit: J. Patrick Fischer; https://commons.wikimedia.org/wiki/File:2009_Andrias_davidianus.JPG]

All three species of giant salamander exhibit paternal care with the male guarding eggs, spending considerable time tail fanning and agitating eggs (Okada et al., 2015) (Figure 2). The first systematic study providing data on paternal from a North American hellbender nest was carried out by Settle et al. (2018). The researchers used unique underwater infra-red video cameras to the record behaviour of a male hellbender in his aquatic nest for a period of five weeks during the breeding season. In this study the male spent 98.4% of the 41.7 hours of observable footage guarding the eggs, rarely leaving them for the whole five week period (Settle et al., 2018). Interestingly, the male was observed to consume its own eggs (filial cannibalism) on seven occasions. The reasons for this are unknown but may either be due to the nutritional value of eggs to the male, or removing eggs that had been contaminated by a fungal infection (Settle et al., 2018). As in other giant salamander species, the male hellbender spent considerable time (60%) fanning the eggs. This is thought to increase oxygen levels in the water and prevent embryo mortality. Overall, this study highlights that male guarding of eggs in hellbenders increases survival of the eggs through decreased predation, increased oxygen levels and potentially removing diseased or dead eggs from the clutch. However, this high level of male guarding comes with several costs including low rate of feeding by the male and increased energy expenditure. Population declines of this North American hellbender could alter the relative costs and benefits of male parental care and impact on survival of populations (Settle et al., 2018).

***Figure 2.*** *Male Japanese giant salamander in his nest guarding the developing larvae. This male is spitting out a larva which had previously entered his mouth.* [Photo credit: Takahashi *et al.* (2017).]

Recently, a new species of leech (Placobdella appalachiensis) and an unknown species of parasitic trypanosome (Trypanosoma sp.), have been found in a population of hellbenders from eastern North America (Hopkins et al., 2014). Research by DuRant et al. (2015) showed that hellbenders infected by leeches had altered physiology compared to unaffected hellbenders. Leeches dampened the immune response of the salamanders, increasing levels of trypanosome infection. In addition, infection with leeches altered the circadian rhythms of the salamanders which impacted on metabolic processes, foraging behaviour and social interactions, particularly during the time of the year when hellbender activity increases as a result of the onset of breeding (DuRant et al., 2015). It is thought that leech saliva directly impacts on the salamander’s physiology since it is known to contain many different hormones and neurosignalling molecules that are believed to directly affect the salamander’s responses to infection. Understanding the dynamics between the leech species to hellbenders is important for conservation of hellbenders which are declining throughout its range. The findings from this study increase our understanding of the physiological effects of leeches on hellbenders and future research needs to examine the possible impacts on reproduction which may influence conservation efforts.

Understanding the longevity of declining species is crucial and provides important information for conservation, such as total lifespan, age of sexual maturity, and age structure of populations in the field (Yamasaki et al., 2017). However, research on longevity in the Japanese giant salamander is lacking since it is not possible to determine age from weight or length. The only reliable method to determine age in salamanders is through skeletochronology. This method is based on the presence of growth layers recorded in cross sections of long bones (Halliday & Verrell, 1988). By taking cross sections of toes, it is possible to count the layers and thus calculate the age of an individual (Figure 3). Yamasaki et al. (2017) are the first researchers to successfully use skeletochronology to estimate age in the Japanese giant salamander. In this study hellbenders lived up to 11 years. Anecdotal observations suggest that this species may live up to 60 years, but this is based on captive specimens. Long-lived species have slow growth rates and long generation times which means they are slow to adapt to environmental change. Therefore further studies on this species will help understand maximum life span and will have implications for conservation of this declining species.

***Figure 3.*** *Growth rings in the Japanese giant salamander. This individual was 11 years old. [*Photo credit: Yamasaki *et al*. (2017)]

References

AmphibiaWeb (2019) Cryptobranchus alleganiensis: Hellbender <http://amphibiaweb.org/species/3861> University of California, Berkeley, CA, USA. Accessed 21 June, 2019.

DuRant, S., Hopkins, W. A., Davis, A. K. & Romero, M. (2015) Evidence of ectoparasite-induced endocrine disruption in an imperilled giant salamander, the eastern hellbender (Cryptobranchus alleganiensis). The Journal of Experimental Biology, 218: 2297-2304. doi:10.1242/jeb.118703.

Gao, K. & Shubin, N. (2003) Earliest known crown-group salamanders. Nature, 422: 424-428.

Halliday, T. R. & Verrell, P. A. (1988) Body size and age in amphibians and reptiles. Journal of Herpetology, 22 (3): 253-265.

Hopkins, W. A., Moser, W. E., Garst, D. W., Richardson, D. J., Hammond, C. I. & Lazo-Wasem, E. A. (2014) Morphological and molecular characterization of a new species of leech (Glossiphoniidae, Hirudinida): implications for the health of its imperilled amphibian host (Cryptobranchus alleganiensis). ZooKeys, 378: 83-101.

Kaneko, Y. & Matsui, M. (2004) Andrias japonicus. The IUCN Red List of Threatened Species 2004: e.T1273A3376261. http://dx.doi.org/10.2305/IUCN.UK.2004.RLTS.T1273A3376261.en. Downloaded on 21 June 2019.

Luo, Q., Tong, F., Song, Y., Wang, H., Du, M. & Ji, H. (2018) Observation of the breeding behavior of the Chinese giant salamander (Andrias davidianus) using a digital monitoring system. Animals, 8: 161. doi:10.3390/ani8100161.

Murphy, R. W., Fu, J. Z., Upton, D. E., De, L. T. & Zhao, E. M. (2000) Genetic variability among endangered Chinese giant salamanders, Andrias davidianus. Molecular Ecology, 9: 1539–1547.

Okada, S., Fukuda, Y., & Takahashi, M. K. (2015) Paternal care behaviors of Japanese giant salamander Andrias japonicus in natural populations. Journal of Ethology, 33: 1–7.

Settle, R. A., Briggler, J. T. & Mathis, A. (2018) A quantitative field study of paternal care in Ozark hellbenders, North America’s giant salamanders. Journal of Ethology, 36: 235–242 https://doi.org/10.1007/s10164-018-0553-0.

Takahashi, M. K., Okada, S. & Fukuda, Y. (2017) From embryos to larvae: seven-month-long paternal care by male Japanese giant salamander. Journal of Zoology, 302: 24–31. Yamasaki, H., Taguchi, Y., Minami, S., Kuwabara, K. & Shimizu, N. (2017) Age determination by skeletochronology of the Japanese giant salamander Andrias japonicus (Amphibia, Urodela). Bulletin of the Hiroshima University Museum, 9: 41-47

Croaking Science: Novel reproductive behaviours in amphibians

April 30, 2019 by editor

There are currently 8,004 species of amphibian (AmphibiaWeb, 2019) of which 88%, (7,064 species) are frogs and toads (anurans). These species exhibit an astonishing range of reproductive modes, of which only a small proportion lay eggs in water which hatch into aquatic larvae. In total, anurans exhibit 40 different modes of reproduction which are based on where the eggs are laid, egg type, and patterns of larval development. Examples of different reproductive modes include: depositing eggs in foam nests which float on water; laying eggs on the back of the female; laying eggs on the ground or in burrows; and depositing eggs on leaves with tadpoles that hatch and fall into water below (Duellman & Trueb, 1986). Of the 40 modes, direct developing embryos are perhaps the most unusual for amphibians. In these species, no water is required for development and instead the tadpoles develop within eggs which then hatch directly into froglets. This type of reproduction has evolved multiple times independently in anurans and currently 1,400 species are recognised to develop in this way (Stuart et al., 2008). Our knowledge of the full range of reproductive modes is still lacking as new patterns of reproduction are still being discovered. For example, some recent discoveries include novel nest building behaviour in the Kumbara night frog (Nyctibatrachus kumbara) from southern India (Gururaja et al., 2014) and unique foot-flagging behaviour has been observed in the Wayanad dancing frog (Micrixalus saxicola) a small torrent frog from India (Preininger et al., 2013). In this article we discuss some further recent discoveries of novel reproductive behaviours in anurans.

The Western Gnats in southern India has been a recent hotspot in discoveries of novel reproductive behaviours in anurans. Due to its glacial history and diversity of habitats, this region supports over 180 species of amphibian which exhibit a range of reproductive patterns. The Chalazodes bubble nest frog (Raorchestes chalazodes) inhabits remote tropical forests in the Western Gnats. This species was presumed to be extinct, until its recent rediscovery in 2011 (Ganesan et al., 2019). Sheshadri et al. (2015), have recently reported a unique breeding behaviour in this frog. Males were found living inside the shafts of bamboo canes where they guarded the eggs laid by the females (Figure 1). It appears that small holes created by insects in the lower shafts of bamboo canes are utilised by this frog, which uses the hollow interior for breeding. Males call to attract females, which lay 5-8 large eggs in clusters inside the bamboo. The male guards these eggs from predators until they hatch into free-living froglets. This is the first time that this type of reproduction has been recorded in any amphibian species and thus represents a unique reproductive mode (Sheshadri et al., 2015). Unfortunately, this frog remains critically endangered, only occurring in five localities, and is highly threatened due to over-harvesting of bamboo (Sheshadri et al., 2015). Unless unregulated overharvest of bamboo is halted, this species may well go extinct due to lack of suitable breeding habitat.Figure 1. Left: Adult Chalazodes bubble nest frog (Raorchestes chalazodes) on top of a bamboo cane; Right: cross section of bamboo cane showing clutch of eggs and an emerging froglet.

***Figure 1.*** *Left: Adult Chalazodes bubble nest frog* (Raorchestes chalazodes) *on top of a bamboo cane; Right: cross section of bamboo cane showing clutch of eggs and an emerging froglet.* [Photo credit: Sheshadri et al., 2015]

Many species of male anuran possess vocal sacs which they use during breeding to vocalise to attract females. In several frog species visual cues of the inflating vocal sac make the acoustic signal more attractive to females or aid to deter competing males. Male African reed frogs (Hyperoliidae) possess a prominent gular patch on the vocal sac which they use to attract females and may also function as a visual cue to competing males (Figure 2). Starnberger et al. (2018) found that in the spotted reed frogs (Hyperolius puncticulatus) males do not respond to the vocal sac of other males but when they heard males calling they performed a previously undescribed gestural display: a tapping behaviour consisting of a series of front and hind limb lifts. It is thought that these gestures serve to deter males and also attract females who may be close by (Starnberger et al., 2018).F

***Figure 2.*** *Male spotted reed frogs (*Hyperolius) often have conspicuous vocal sacs which they use to vocalise and attract females. [Photo credit: Luke & Ursula Verburgt, http://africanamphibians.myspecies.info/file-colorboxed/8072]

Many anurans form amplexus during breeding where by the male takes the female in an embrace. Since fertilization is external in most anurans, the position of the male ensures that he is able to release his sperm to fertilize her eggs as she releases them. The night frogs (genus Nyctibatrachus) from India contains 28 species, many of which have only recently been described. In all Nyctibatrachus species, egg clutches are deposited on rocks or vegetation overhanging water, and tadpoles fall in the water after hatching, where they continue their development. Several novel types of amplexus have been described in this genus (reviewed in Willaert et al., 2016) such as a short axillary amplexus in pairs of the Kumbara night frog (N. kumbara) followed by a handstand, or the complete absence of amplexus in N. petraeus where the female deposits her eggs prior to the male fertilizing them. Willaert et al. (2016) have recently discovered a new breeding behaviour in the Bombay night frog (N. humayuni). During breeding the male forms a loose amplexus on the female, lasting only a few seconds and differs from all previously described amplexus types in anurans. When mounted, the male rests on the female without grabbing her tightly, but instead uses his hands to hold on to a leaf, branch or tree trunk (Willaert et al., 2016). Since the male does not have time to fertilise the eggs whilst engaged with the female, the authors propose that the male releases his sperm onto the back of the female and the eggs are subsequently fertilized by the sperm running down her back and hind legs. This hypothesis is supported by the observation that the female remains motionless after egg deposition for several minutes with her hind legs stretched around the freshly deposited clutch (Willaert et al., 2016) (Figure 3). In addition, females have been observed to make a call which is highly unusual. Female calling behaviour has so far only been reported in only 25 anurans, representing less than 0.5% of the total anuran species that are currently recognized (Willaert et al., 2016). It appears that the females call to aid in mate recognition and location.

***Figure 3.*** *A female Bombay night frog (*N. humayuni) *deposits hers eggs and remains motionless with her hind legs stretched around the eggs. The male is sitting close-by without any physical contact with the* female. [*Photo credit: Willaert et al., 2016]*

This study, along with others recently published, demonstrate the range of reproductive behaviours that are exhibited amongst anurans. The Nyctibatrachus frogs are one of several unique taxa in the Western Ghats biodiversity hotspot and are heavily threatened by human activities. Understanding the ecology of these and other poorly known species is of major importance for planning and successfully implementing conservation strategies.

References

AmphibiaWeb (2019). <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 18 Apr 2019.

Duellman, W.E. & Trueb, L. (1986) Biology of Amphibians, McGraw-Hill Publishing Company, United States of America.

Ganesan, R., Seshadri, K.S. & Biju, S.D. (2019) Lost! Amphibians of India. Available at: http://www.lostspeciesindia.org/LAI2/new1_rediscovered.php. Accessed 18 April 2019.

Gururaja, K.V., Dinesh, K.P., Priti, H. & Ravikanth, G. (2014) Mud- packing frog: a novel breeding behaviour and parental care in a stream dwelling new species of Nyctibatrachus (Amphibia, Anura, Nyctibatrachus). Zootaxa, 3796: 33-61.

Preininger, D., Boeckle, M., Freudmann, A., Starnberger, I., Sztatecsny, M. & Hödl M. (2013) Multimodal signaling in the Small Torrent Frog (Micrixalus saxicola) in a complex acoustic environment. Behavioral Ecology and Sociobiology, 67: 1449–1456.

Seshadri, K.S., Gururaja, K.V. & Bickford, D.P. (2015) Breeding in bamboo: a novel anuran reproductive strategy discovered in Rhacophorid frogs of the Western Ghats, India. Biological Journal of the Linnean Society, 14 (1): 1-11. https://doi.org/10.1111/bij.12388

Starnberger, I., Maier, P.M., Hödl, W. & Preininger, D. (2018) Multimodal signal testing reveals gestural tapping behavior in spotted reed frogs. Herpetologica, 74 (2): 127–134.

Stuart, S.N., Hoffmann, M., Chanson, J.S., Cox, N.A., Berridge, R.J., Ramani, P. & Young, B.E. (2008) Threatened Amphibians of the World. Barcelona, Spain: Lynx Edicions; Gland, Switzerland: IUCN, Arlington, Virginia, USA: Conservation International.

Willaert, B., Suyesh, R., Garg, S., Giri, V.B., Bee, M.A. & Biju, S.D. (2016) A unique mating strategy without physical contact during fertilization in Bombay Night Frogs (Nyctibatrachus humayuni) with the description of a new form of amplexus and female call. PeerJ 4:e2117; DOI 10.7717/peerj.2117

CJ Wildlife – Your Spring Offer!

January 31, 2019 by editor

This month, CJ Wildlife – Europe’s leading garden wildlife specialist and Froglife partner are reminding us that all of our gardens, no matter what size, can become bustling nature reserves for our local wildlife, so the more species you can cater for – from the smallest insect to the largest toad – the more alive your garden will become this spring.

We’re now in the last full month of winter and, whatever February throws at us, spring isn’t too far away. Hedgehogs and bats should still be hibernating, but the first squirrel litters are likely to be born anytime and, by the end of the month, an increasing number of ponds will have frog spawn.

Birds will be looking for nesting territories, which makes February the ideal month to put up a new nest box and keeping feeders topped up will ensure birds know they can rely on your garden for a reliable source of food, vital when choosing somewhere to raise their young.

For hints and tips on making the perfect wildlife garden this spring, visit www.birdfood.co.uk, plus as a Froglife supporter, you can save 10% off when you buy from CJ Wildlife, simply use discount code UKFROG18 when you order.

What our Animals are doing this month…

January 31, 2019 by editor

What our animals are doing this month…. February 2019 Edition

It’s probably not quite hot enough for many of our amphibians to get back into the swing of things, but by mid to late February it’s likely some amphibians will be moving back to ponds and for our common frog even breeding / laying frogspawn.

Smooth newts may have made their way back to ponds within the month of February after traversing some difficult terrain on their travels from overwintering areas to a pond. But how do they make this journey through what may be areas of tall, dense vegetation back to their breeding pond? The majority of amphibians return to the same pond year after year – hence they must have some form of navigation. For smooth newt and great crested newt, they use their sense of smell to navigate back to the pond as well as the calls of common toad. However, if smooth or great crested newts are displaced away from their home range – their sense of smell and hearing won’t be adequate to navigate back to their preferred pond.

The palmate newt has displayed an additional method of navigation however using a sense called magnetoreception. This sense acts a geomagnetic compass the palmate newt can use to find its way back to its breeding pond, even if displaced up to 19km outside of its range.

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